Combined feed mechanism with stepped feed-dogs for sewing machines



1963 A. c. PETERS-ON ET AL 3,416,473 comamsu FEED MECHANISM WITH STEPPED FEED-DOGS m m 1 m v m. mmm m w mm A w .:l mum m c A H s ER A A W a m FOR SEWING MACHINES Filed Feb. 1. 1965 A; c. PETERSON E Al.

Dec. 17, 1968 3,416,413

COMBINED FEED MECHANISM WITH STEPPED FEED-DOGS FOR SEWING MACHINES 4 Sheets-Sheet 2 Filed Feb. 1, 1965 v mil 09 2 1| 3 r N g M J V mm Ev M s $11M i mmw I nn l unununl J CAHHH @r m ARR hm. C .\\+v\L W- F mm, e mq Q M a 8 mdfi. M, 8 a N. N \Sd. u m m f F ATTORNEYS Dec. 17, 1968 A. cl PETERSON ET L COMBINED FEED MECHANISM WITH STEPPED FE 3,416,473 ED-DOGS I FOR SEWING MACHINES Filed Feb. 1, 1965 4 Sheets-Sheet 5 S S m w T M W m Ima A a v. am A W W B A. c. PETERSON ETAL 3,416,473 COMBINED FEED MECHANISM WITH STEPPED FEED-DOGS FOR SEWING MACHINES Dec. 17, 1968 v INVEN'i'ORS, A .C PETERSON, 1 R. A. HAYEs 9" R.H. LUKHJS ZQ VMQMZQ 4 Shets-Sheet 4 Filed Feb. 1, 1965 ATTORNEYS United States Patent 3,416,473 CDMBINED FEED MECHANISM WITH STEPPED FEED-DOGS FOR SEWING MACHINES Albert C. Peterson, Park Ridge Manor, Robert A. Hayes,

Franklin Park, and Richard H. Lukins, Glen Ellyn,

Ill., assignors to Union Special Machine Company,

Chicago, 111., a corporation of Illinois Filed Feb. 1, 1965, Ser. No. 429,583 14 Claims. (Cl. 112-209) ABSTRACT OF THE DISCLOSURE A multiple needle felling machine of the feed-otf-thearm type wherein there are included a main feed bar and a differential feed bar, a main drive shaft, means con necting each bar with the main drive shaft, means for varying the motion of the differential feed bar relative to the motion of the main feed bar, each bar having a vertically adjustable feed-dog with a front portion higher than the rear portion and both portions of the differential feed-dog higher than both portions of the main feed dog.

The following description relates to the details of a novel differential feed mechanism with stepped feed-dogs adapted for multiple felling on various types of sewing machines, but especially for use on the well known feedoff-the-arm machines.

The standard multi-needle felling machines of the feedoif-the-arm type at present do not have a differential feed mechanism.

It has been found that in sewing and joining Sanforized fabrics and other materials by means of a lap seam arrangement, ofttimes a considerably curved seam is produced, due to the characteristics of the fabrics and or even the tension which the operator applies to each of the fabric plies as she holds them and guides them through a customary lap seam folder.

By dividing the feed-dog and installing one part as a separate feed-dog on a differential feed bar, it is possible to produce pucker-free, straight lap seams and the two pieces of material will be even at the end of the seaming operation. This is due to the fact that the two feed-dogs can be adjusted relatively to provide the necessary feed action to suit the characteristics of the material being seamed and the material handling habit of the operator.

It has been shown to provide a feed-dog in felling machines with a raised or stepped portion. Despite the stepped feed-dogs, difficulty has been encountered in producing puckerfree, straight seams and having the two portions or plies of fabric which are being seamed, come out even. To meet this difficulty it has been necessary to provide shims for raising the right-hand row of teeth on the feed-dog, the requisite amount to effect even seaming of the plies of fabric. This raising or lowering of the right hand row of teeth by means of shims is difficult. It is obviously time consuming, since it requires the removal of some of the parts of the machine in order to remove or insert the necessaiy shims. Even so, such adjustment is uncertain because it is quite unlikely that the mechanic would be expert enough to get the exact adjustment which he expects.

On the other hand, by having the right-hand row of upper level teeth carried by a differential feed bar, the mechanic or even the machine operator can easily adjust the feed mechanism so as to feed both edges of the material exactly the right amount to suit the material being sewed and the work-handling ability of the machine operator.

It is an object of this invention to provide a multiple 3,416,473 Patented Dec. 1 7, 1 968 thread felling machine of the off-the-arm type with a novel differential feed mechanism.

It is another object of the invention to combine such a differential feed mechanism in such machines with stepped feed-dogs.

A further object of the invention is to provide an independently adjustable feed for the differential feed mechanism.

Among the objects of the invention is to provide separate feed for the differential feed mechanism to vary the advance of one ply of fabric relative to another ply.

A still further object of the invention is to assure that each of the main and differential feed-dogs has front teeth which extend at a higher level than the teeth at the rear of the respective feed-dogs.

Another object of the invention is to provide a multiple needle lap seam sewing machine equipped with a stepped throat plate and a lower four-motion feed-dog, and a lower four-motion differential feed-dog arranged alongside of the needles and at a higher level than the main feed-dog.

An incidental object of the invention is to space the main feed-dog so that one portion extends in front of the needles while a second portion operates in the Zone rearwardly of the needles.

In the present arrangement, both of the feed-dogs have the teeth in the front portion of the dog arranged at a higher level than the teeth in the rear portion of the dog. The purpose of this arrangement is to provide each dog with a slightly gathering action in feeding the material. This aids in producing flat, pucker-free seams. In other words, the front or high portion of each dog feeds a slightly greater amount than the rear or low portion. This slightly greater feeding action by the front portion of each dog results because the teeth in this front portion of the dog rise above the top of the throat plate sooner than the teeth in the lower rear section of the dog. Furthermore, the front teeth remain above the throat plate longer than the rear teeth do. Hence the front teeth of each dog have a slightly greater feeding action than the rear lower teeth of that dog.

While this type of feed dog has been used in earlier machines, it has not been used as a part of a differential feed mechanism.

In connection with the various features above indicated, it should be noted that the stroke of both feeddogs can be increased or decreased simultaneously. Also, the stroke of the differential feed-dog can be increased or decreased separately by an independent adjusting lever.

The preferred form of this invention has been illustrated for purpose of example on the accompanying drawings in which:

FIGURE 1 is a side elevation partly in section of sewing machine embodying the invention;

FIGURE 2 is a plan view of the sewing arm of the machine with cover removed and portions of the base broken away;

FIGURE 3 is an enlarged partial plan view of the serving arm, both feed-dogs being shown;

FIGURE 4 is a fragmentary transverse vertical crosssection on line 44 of FIGURE 3, the throat plate and both feed dogs being shown;

FIGURE 5 is an enlarged fragmentary vertical longitudinal section on the line 5-5 of FIGURE 3, showing the feed-dogs and loopers;

FIGURE 6 is a fragmentary side elevation of differential levers and linkage appearing in FIGURE 1 FIGURE 9 is a transverse vertical cross-section on line 9-9 of FIGURE 1, omitting the looper throw-out pitman;

FIGURE 10 is a perspective view of the new differential feed-dog and FIGURE 11 is a perspective view of the related main feed-dog.

The combined feed mechanism with stepped feed-dogs is incorporated as a part of the feed-oif-the-arm sewing machines of well known type, as illustrated on the drawmgs.

Here the sewing machine consists in general of a main base portion 12 adapted to be supported in the usual manner on a table, not illustrated. The base portion extends upwardly and horizontally to form a horizontal extension 13. At the end of the portion 13 there is provided the usual needle head 14.

The opposite end of the main base portion consists of a hollow depending standard 15.

A horizontal work-supporting arm 16 extends outwardly from the standard to a point beneath the needle head The horizontal extension 13 carries suitably aligned bearings of which only one, namely bearing 17 is shown on FIGURE 1. These bearings carry the rotary main drive shaft 18. This drive shaft extends beyond the needle head 14 and at its end carries a combined hand wheel and pulley 19.

The usual needle bar 20 is slidably carried in the needle head. Two or more needles 21 extend downwardly from the needle bar 20.

Loopers 22 are mounted in a looper holder 22a within the work-supporting arm 16. These loopers are located beneath the needles 21 and the intervening feed-dogs. The loopers 22 are operated by means of a looper rock shaft 23. This extends within the work-supporting arm to a point beneath the depending standard 15.

A link 24 connects the looper shaft 23 to a strap 25. The strap 25 surrounds an eccentric 26 formed as part of the end of the main drive shaft 18. See FIGURES l, 2 and 9. This arrangement is similar to what is shown in the prior patent of N. V. Christensen 2,372,175, to which reference is made for further minor details.

A plunger 27 is slidably mounted vertically in the top of the standard 15. This constitutes a looper throw-out operating with the eccentric 26 in the manner illustrated in the prior patent to C. C. Smith, 2,391,519.

Needle avoid means is provided for the looper shaft 23 by means of a rocking lever 28 transversely mounted in the arm 16. See FIGURES 1, 2 and 9. This shaft receives oscillatory motion through the pitman 29 (FIGURES 1 and 2), which has a strap 30 surrounding an eccentric 31 on the main shaft 18.

The main feed-dog 32 has a slotted shank 33. A main feed bar 34 FIGURES 1 and 2 extends within the supporting arm 16.

Midway of the arm 16 there is a transverse pivot pin 35. (See FIGURES 1 and 2.) This carries a loose block 36. The main feed bar 34 is recessed as shown in FIGURE 1 to form a slide bearing to receive the pin 35 and block 36.

The end of the main feed bar 34 carries a screw on the stem of which the slotted shank of the main feed-dog 32 is vertically adjustable, as clearly shown in FIGURES 1, 2 and 5.

The inner end of the feed bar 34 carries a threaded ball pin 38 as best shown in FIGURE 2. A pitman 39' has a strap 40' on its lower end surrounding the ball pin 38. The upper end of the pitman 39 has a split strap 41. This strap fits on an eccentric 42 on main drive shaft 18. The strap 41 and the eccentric 42 have spherical bearing surfaces. By the means thus described, rotation of the main drive shaft 18 will cause rise and fall movements to the main feed bar 34 which are imparted to feed-dog 32.

A differential feed bar 43 is provided and is also recesed at an intermediate lower point, as is the feed bar 4 34, as shown in FIGURES 1 and 2. This recess receives the supporting block 36. The block is held in position in this recess and that of the main feed bar 34 by means of the cover plate 44.

The front end of the differential feed bar 43 supports an auxiliary differential feed-dog 45 by means of a dependent slotted shank 46 and an adjusting screw 47 on the side of the feed bar 43.

The opposite end of the differential feed bar 43 has a lateral yoke 37. This yoke fits slidably around the shank of the threaded ball pin 38, with which it is constrained to move vertically, as shown in FIGURE. 2.

It will thus be apparent that the rocking motion of the feed bars 34 and 43, imparted thereto in the manner herein described, provides for the desired rise and fall motions of the feed dogs carried thereby.

The longitudinal movements of the main and differential feed bars 34 and 43 are imparted from an arm 48 extending upwardly from the rock lever 28. Arm 48 is provided with an elongated .arcuate slot 49 adapted to receive a bolt 50 which may be adjusted to any desired position along the slot and set to provide the desired feed stroke for the main feed-dog 32. A link 51 pivotally connected with the bolt 50 is at its opposite end connected by a screw stud 52 to the arm 53. The arm 53 is slotted longitudinally as shown in FIGURES 1, 6 and 8. It extends upwardly from a sleeve 54 rockably mounted on the shaft 55. Another upwardly extending arm 56 integral with the sleeve, is connected by a secured screw stud 57 with a link 58, which at its opposite end is connected by a screw stud 59 with the main feed bar 34. The arm 53 in its elongated slot receives a screw stud 60 at the inner end of the link 61. At its opposite end, link 61 is pivotally connected by a screw stud 62 with the differential feed bar 43. See FIGURES 1 and 6. The position of the stud 60 along the slot in the arm 53 may be varied at will by lifting the inner end of the link 61. For this purpose there is attached to this link, by a screw stud 63, a downwardly extending link 64, the lower end of which is connected by a stud 65 with an arm 66 freely journaled upon the shaft 55 adjacent the arm 53. See FIGURES 6 and 8.

An upwardly extending arm 67 of the same member is slotted longitudinally as will be apparent by reference to FIGURES 1 and 8. The adjacent wall of the work supporting arm carries a dial plate 68 having a central bearing 69. This bearing plate carries a shaft 70. See FIGURES 2, 7 and 8. A lever 71 and a fiat spring 72 are attached to the shaft by means of screw 73. A pin 74 on an arm 75 secured on the shaft 70 slides within the slot of the arm 67, as shown in FIGURE 8.

The outer end of the work-supporting arm 16 supports a throat plate 76 beneath the needles 21, as shown in FIGURES 1 and 3. This plate has a raised land 77 along one longitudinal side, as best shown in FIGURES 3 and 4. The land has a feed slot 78 disposed longitudinally therein.

The lower surface of the throat plate has a series of parallel slots 79. These are at one side of the raised land 77 and substantially as long as the feed slot 78 in said raised land. The throat plate has a group of the usual needle slots 80, appropriately spaced.

The feeding surface of the stepped main feed-dog 32 (FIGURE 11) has several rows of teeth 81, here shown as four in number. These teeth register in the lower slots 79 of throat plate 76, as shown in FIGURES 3 and 4. The teeth in the forward section of the feeddog 32 are shown as of greater height than those in the rear. In normal operation, these rows of teeth rise through the slots 79 with a forward feeding motion.

The differential feed-dog 45 (FIGURE 10) has a single row of teeth 83. These teeth are of two heights, the shorter one 84 being higher than those in the section 82 of the main feed-dog, as will be clearly apparent by reference to FIGURE 5. The section of teeth 85 in the front portion of the differential feed-dog 45 are higher than those in the portion 84- and even higher than the highest teeth in the main feed-dog, as will also be apparent by reference to FIGURE 5.

It will be apparent by reference to FIGURES 3 and 4 that the main and differential feed dogs designated 32 and 45, respectively, are arranged in side-by-s ide relation and extend in the direction of feed for operating on separate pieces or side-by-side portions of the'work in the manner best illustrated in FIGURE 4. When two or more plies 86, 87 of material such as woven or knitted fabric and the like, are fed through the usual folder (not shown) and under the needles they are subjected to the action of the presser foot members 88, 89, so that appropriate engagement is effected on the material by the several rows of teeth of different height, as clearly shown in FIG- URE 4.

Guide plates 90, 90 are attached to the top surface of the work supporting arm cover 91 in advance of the throat plate 76.

From the foregoing it should be apparent that as the feed bars 34 and 43 are rocked about their pivotal mounting at 35 by action of the eccentric and pitman connectioins 42, 39, 38 and the yoke connection 37 between said pin 38 and the feed bar 43, as previously described, the desired rise and fall motions of the feed dogs 32 and 45 carried by said feed bars will be provided. Adjustment of the position of the bolt 50 in the slot 49 of the arm 48 rocked by the pitman and eccentric connections 29, 31 from the main shaft 18 will enable a varying of the amount of horizontal movement of the feed bar 34 through 58, 56, 54, 53 and 51 and of the feed bar 43 through 61, 53, 51, as will be apparent by reference to FIGURES 1, 2, 6, 8 and 9. It follows also that adjustment of the bolt 60 in the slot of the arm 53 by the previously described manual adjustment of the lever 71 and the crank and link connections 67, 66, 64 and 61 will enable a varying of the amount of horizontal movement of the feed bar 43 through 61, 53, 51 relative to the movement being imparted to the feed bar 34 as aforesaid, the spacing of the bolt 60 from the rocking center of the arm 53 and therefore the degree of thrust imparted to the feed bar driving link 61 thus being varied.

The machine described above in detail provides ready means under the control of the machine operator to differentiate between the feed of the separate plies of material being sewn on a felling machine of the feed-offthe-arm type. This finds its most important function in the case of two or more plies of different characteristics and requiring different rates of feeding in order that the seam shall be flat and the material fed evenly.

To accomplish'this result, stepped feed-dogs are utilized with individual characteristics accomplishing the above result.

In carrying out the purposes, the front teeth of both the main and the differential feed-dogs are given greater height than the rear teeth of the respective feed-dogs.

The arrangement provides a multiple needle lap seam sewing machine having a stepped throat plate and a lower four-motion feed-dog together with a lower four-motion differential feed-dog alongside of the needles, but at a higher level than the main feed-dog.

By using a stepped main feed-dog with a stepped differential feed-dog in this type of machine, a slightly greater feeding action of the front portions of the feeddogs is combined with the effect of the lifferential feed mechanism. The raised or front portion of both feed-dogs engages the material earlier in the cycle and advances it for a longer period of time than is done by the lower or rear portions of the feed-dogs. This is effective to produce a slight gathering of the material which may be necessary in order that the completed seam will be in the form desired.

The preferred form of the invention has been described and illustrated, it being understood that the purposes of the invention can, however, be accomplished by minor changes in individual parts and arrangements within the scope of the invention as defined in the following claims.

What We claim is:

1. In a multiple needle felling machine, a main feed bar and a differential feed bar, a stepped feed dog on each bar, said stepped feed dogs being disposed in sideby-side relation and extending in the direction of feed for operating on separate pieces of work, a main drive shaft, means connecting each bar with the main drive shaft and means for varying the degree of longitudinal motion of the differential feed bar relative to the motion of the main feed bar.

2. In a multiple needle felling machine, a main feed bar and a differential feed bar, a vertically adjustable stepped feed dog on the main feed bar, a vertically adjustable stepped feed dog on the differential feed bar, said stepped feed dogs being disposed in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, a main drive shaft, means connecting each bar with the main shaft and means for varying the degree of longitudinal motion of the differential feed bar relative to the motion of the main feed bar.

3. In a multiple needle felling machine of the feed-offthe-arm type, a main feed bar and a differential feed bar, a vertically adjustable stepped feed dog on the main feed bar, a vertically adjustable stepped feed dog on the differential feed bar, said stepped feed dogs being disposed in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, a main drive shaft, means connecting each bar with the main shaft and means for varying the degree of longitudinal motion of the differential feed bar relative to the motion of the main feed bar.

4. In a multiple needle felling machine of the feed-offthe-arm type, a main feed bar and a differential feed bar, a vertically adjustable stepped feed dog on the main feed bar, a vertically adjustable stepped feed dog on the differential feed bar, said stepped feed dogs being disposed in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, a main drive shaft, means connecting each bar with the main shaft and operator controlled means for varying the motion of the differential feed bar relative to the degree of longitudinal motion of the main feed bar.

5. In a multiple needle felling machine of the feed-offthe-arm type, a main feed bar and a differential feed bar, a main drive shaft, means connecting each bar with the main drive shaft, means for varying the motion of the differential feed bar relative to the motion of the main feed bar, each bar having a vertically adjustable feed-dog with a front portion higher than the rear portion and both portions of the differential feed-dog higher than both portions of the main feed dog.

6. In a multiple needle felling machine, a main feed bar and a differential feed bar, a main drive shaft, means connecting each bar independently with the main drive shaft, each of said feed bars having a toothed working surface steppedin the direction of travel of the work, and the differential feed bar having its toothed working surface higher than that of the main feed bar.

7. In a multiple needle felling machine, a main feed bar and a differential feed bar, a main drive shaft, means connecting each bar independently with the main drive shaft, said feed bars each having two stepped portions in the direction of travel of the work, and the lower stepped portion of the differential feed bar being higher than the upper stepped portion of the main feed bar.

8. A sewing machine comprising a differential work feed mechanism having main and differential feed bars provided with toothed working surfaces in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, at least one of said feedbars having two stepped toothed Working surfaces, a main drive shaft, means connecting each feed bar with the drive shaft, and means for imparting lifting and lowering movement and also generally horizontal movement to the feed bars and including devices for imparting a determined generally horizontal movement to both feed bars and other devices for varying the degree of generally horizontal movement imparted to one of the feed bars relative to the other.

9. A sewing machine as defined in claim 8 wherein the first mentioned devices also include means for varying the degree of movement to be imparted thereby.

10. A sewing machine comprising a differential work feed mechanism having main and differential feed bars provided with toothed working surfaces in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, at least one of said feedbars having two stepped toothed working surfaces, a main drive shaft, means connecting each feed bar with the drive shaft, means for varying the motion of the differential feed bar relatively to the motion of the main feed bar and feed dogs attached to the respective feed bars, said toothed working surfaces being provided on said feed dogs.

11. A sewing machine comprising a differential work feed mechanism having main and differential feed bars provided with toothed working surfaces in side-by-side relation and extending in the direction of feed for operating on separate pieces of work, at least one of said feedbars having two stepped toothed working surfaces, a main drive shaft, means connecting each feed bar with the drive shaft, means for varying the motion of the differential feed bar relatively to the motion of the main feed bar and feed dogs attached to the respective feed bars, said toothed working surfaces being provided on said feed dogs, and in which the connections from the drive shaft to the feed bars enable the stroke of the feed bars to be varied simultaneously, and in which the means for varying the motion of the differential feed bar comprises an operatorcontrolled lever.

12. A sewing machine as defined in claim 10 including a throat plate having a stepped upper surface formed by a raised land extending along one longitudinal side, said land including a feed slot extending longitudinally thereof and registering with a single row of teeth on the differential feed-dog, said throat plate including a series of slots extending through the lower surface in parallel relation with one another and with said feed slot, said slots registering with corresponding rows of teeth on the main feeddog, and the throat plate including needle-registering slots arranged substantially midway between the ends of the throat plate.

13. A multiple needle felling machine, comprising a main feed bar and a differential feed bar, a main drive shaft, means connecting each bar independently with the main drive shaft, said feed bars having two toothed working surfaces in side-by-side relation and stepped in the direction ,of travel of the work for operating on separate piecesof work, and the lower stepped portion of the differential feed bar being higher than the upper stepped portion of the main feed bar.

14. A sewing machine as defined in claim 13 including feed dogs attached to the respective feed bars, the toothed working surfaces being provided on said feed dogs, each said feed dog being vertically-adjustably mounted on its respective carrier feed bar.

References Cited UNITED STATES PATENTS 423,816 3/1890 Robinson 112216 1,581,222 4/ 1926 Moifatt 112216 2,134,329 10/1938 Ebert 112209 2,667,851 2/1954 Knaus et al. 112-209 FOREIGN PATENTS 1,132,780 5/1962 Germany.

' JORDAN FRANKLIN, Primary Examiner.

H. HAMPTON HUNTER, Assistant Examiner.

US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,4l6,473 December 17 1968 Albert C. Peterson et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, lines 12, 23, 33, and 43, before motion", each occurrence,

insert degree of longitudinal Signed and sealed this 24th day of March 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr. Attesting Officer Commissioner of Patents 

